Pebax/SAPO-34混合基质膜的制备及性能研究

Preparation and characterization of Pebax/SAPO-34 mixed matrix membrane

选用Pebax1657和SAPO-34为膜材料,分别采用醋酸和1-丁醇为溶剂,通过流延法制备Pebax/SAPO-34混合基质膜(MMMs).研究发现,溶剂能显著地影响膜的结构形态以及渗透性能.纯Pebax膜的气体渗透系数受溶剂的影响较大,而选择性受溶剂影响不大.对于分子筛含量较高(质量分数33%)的MMMs,以1-丁醇为溶剂时,分子筛的分散均匀程度更高,但就材料的成膜性而言,醋酸为溶剂时更好.MMMs中气体渗透系数的变化是结晶度、扩散曲度、链段运动能力和膜形态等因素的共同作用的结果.醋酸为溶剂时,由于相分离的发生,气体的渗透系数出现突跃,最大提高到纯Pebax膜的3倍.1-丁醇为溶剂时,除H2外,气体渗透系数先出现一定程度的提高,而后由于受到链段僵化以及扩散曲度的影响而降低.

Poly（amide-6-b-ethylene oxide）（Pebax1657）and SAPO-34 were used to prepare Pebax1657/SAPO-34 mixed matrix membranes（MMMs）by solution-casting method with 1-butanol and acetic acid as solvent respectively.It was found that the casting solvent had more influence on permeability rather than selectivity.The MMMs prepared with 1-butanol had better zeolite distribution at high zeolite content,but the better membrane-forming was belonged to that prepared with acetic acid.The change of permeability was the co-effect of crystallization,diffusivity tortuosity,mobility of polymer chain and membrane morphology.When acetic acid was used,due to the phase separation,the permeability showed a jump and maximum reached 3fold of the pristine Pebax membrane,and when 1-butanol was used,except for H2,the permeabilities of other gases increased initially and then decreased as a result of chain rigidification and increased diffusivity tortuosity.